import Color from 'color'
import { decrypt, encrypt } from 'romulus-js'
import { DEFAULT_KEY, MessageTypes } from '../common'
import { numberToUint16BE } from '../utilities/number'
import { SmartBuffer } from '../utilities/smart-buffer'
import { packOutgoingPacket } from './packet'

const MESSAGE_TYPE = numberToUint16BE(MessageTypes.UserDataRequest)

export interface UserDataRequestMessage {
  username: string
  colour: Color
  clientId: string
}

/**
 * Create an outgoing user data request (0x0002) packet.
 * @param properties The properties for the message.
 * @param key The key to encrypt the data with.
 * @returns An outgoing user data request (0x0002) packet.
 */
export function packUserDataRequestMessage (properties: UserDataRequestMessage, key: Uint8Array = DEFAULT_KEY): Uint8Array {
  const encoder = new TextEncoder()

  // Prepare data in correct format.
  const username = encoder.encode(properties.username)
  const usernameLength = numberToUint16BE(username.length)
  const colour = new Uint8Array(properties.colour.array())
  const clientId = encoder.encode(properties.clientId)
  const clientIdLength = numberToUint16BE(clientId.length)

  // Pack data.
  const packedData = new SmartBuffer()
  packedData.writeBytes(usernameLength)
  packedData.writeBytes(username)
  packedData.writeBytes(colour)
  packedData.writeBytes(clientIdLength)
  packedData.writeBytes(clientId)

  // Encrypt the data.
  const data = encrypt(packedData.data, MESSAGE_TYPE, key)

  return packOutgoingPacket({
    messageType: MESSAGE_TYPE,
    data: data
  })
}

/**
 * Unpack the decrypted data section of an incoming user data request (0x0002) message.
 * @param data The decrypted data section of an incoming user data request (0x0002) message.
 * @returns An unpacked user data request (0x0002) message.
 */
export function unpackUserDataRequestMessage (data: Uint8Array): UserDataRequestMessage {
  // Unpack and read data in correct format.
  const packedData = SmartBuffer.from(data)

  const usernameLength = packedData.readUInt16()
  const username = packedData.readBytes(usernameLength)
  const colour = packedData.readBytes(3)
  const clientIdLength = packedData.readUInt16()
  const clientId = packedData.readBytes(clientIdLength)

  const decoder = new TextDecoder()

  // Return data in correct format.
  return {
    username: decoder.decode(username),
    colour: Color.rgb(colour),
    clientId: decoder.decode(clientId),
  }
}